<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        function changeCode(){
            let imgObj=document.getElementById("codeImg");
            imgObj.src="/checkCode?"+Math.random();
        }
    </script>
</head>
<body>
<form action="user/land" method="post">
    用户名：<input type="text" name="name"><br>
    密码： <input type="text" name="pwd"><br>

    <img src="/checkCode" id="codeImg"><a href="javascript:changeCode()">看不清楚？换一张！</a><br>
    验证码：<input type="text" name="userCode"><br>
    <input type="submit" value="登录">
</form>
</body>
</html>